Journey of the Boardwalk: Part 24 - New Kojak Tires

It has been almost 2 months since I last blogged about my Dahon Boardwalk! The truth is, there isn't much more I can upgrade and write about, since I have already upgraded everything on the bike.

While browsing through some older photos of my Boardwalk, I realised that the Kojak tires have been on my bike for quite a while. Looking at the date on the photos, it has been 21 months since I first installed this pair of Kojak tires! Now, there are a few components on a bike that can be considered consumables, meaning that they will wear out and eventually have to be replaced. Here is a short list of these components:

1) Tires. Depending on the brand and type of tires, can typically last at least 2000km.
2) Brake Pads. Wear rate is very dependent on weather conditions and riding conditions, not so much on mileage. Brake pads wear much faster in the rain and in the city where braking is done more often.
3) Chain. Can usually last thousands of miles before stretching too much, but they are usually changed out earlier due to rust or bike upgrades.
4) Cassette & Chainring. They will eventually wear out, but it takes a lot of mileage to wear them out. The teeth will become sharp as the chain wears down the gear teeth.

Of course, actual wear rate and lifespan of these components depend a lot on riding conditions and frequency of maintenance.

For me, the cassette and chainring wear is not a problem since I have been upgrading my bike, and the Shimano Ultegra crankset and 105 cassette are relatively new. Same for the chain, switching from 7/8 to 9 and now 10 speed Dura-Ace 7901 chain. The brake pads are not so new, but the wear rate can be easily seen, and they look fine so far. Plenty of thickness and life left.

As for the Kojak tires, it is not so easy to detect wear. Unless you really use your tires until the rubber wears out and the carcass of the tire is seen, it is hard to tell that your tires are worn, especially if you are using slick tires with no treads.

My rough estimate puts the mileage of the Kojak tires at 3000+ km, probably close to 4000km. No problems with the tires so far, apart from being tight on the rims, making it a PITA to remove from the rims. This is partly due to the wire bead type of Kojak that I am using.

On the surface of the tires, I can actually see many small dots on the tires, much like the surface of a sponge cake. It is hard to estimate the remaining lifespan of the tires, but this is probably an excuse for me to change to new tires!

Besides the Schwalbe Kojaks, the other tires that I have considered are the Duranos, which are narrower and faster tires. The Duranos are 1.1" wide, compared to 1.35" width of the Kojaks. It is excellent if you are looking for pure speed, but since I do carry stuff and do some light touring with my Boardwalk, I felt that the Kojaks are still the best tires that suit my purpose. Narrow and slick enough for fast riding, and yet wide and cushy enough to handle some load and less than perfect roads. Lower tire pressure is required, which makes it less prone to punctures. In this case, there is no good reason to change to another type of tires, since the Kojaks work so well.

Small holes on the tires, a result of normal wear and tear

New Kojak tires!!! Love the smell of fresh rubber

The new Kojak tires has the words and logo printed with reflective paint, brilliant for side visibility at night.

The new Kojak logo design, compared to the older Kojak tire.

Comparing the surface of the new and old tires.

I got the Kojak tires with a Kevlar bead, which means that the tires can be folded, and the flexible bead also makes it easier to install and remove the tire from the rims. Moreover, the Kevlar version is lighter at 230g each, compared to 290g each for the wire bead version.

Together with the super light Schwalbe tubes (SV 6A), the tires and tubes weigh less than 600g in total, down from around 800g. Probably too little to feel while carrying the bike, but since these are rotating mass at the edge of the wheels, it might just make a little difference.

New tube and tire, ready to go onto the rim

Nice contrast, especially with a brand new tire!

Love the reflective words!

 Close up look at the Kojak logo and the Wheelsport logo

 

The rear wheel also gets a new tire

 I'm sure you can tell that I really like the glowing logo!

Cycled 20+ km on the new tires today, no problems at all. Feels the same, not faster or slower. Pleased with the new rubber on the bike, the tires are ready to roll for another 4000 to 5000km!

Caliper Brakes and Stem for the Vitesse P18-TT

In a previous post, I documented how a Dahon Vitesse P9 was converted to a Vitesse P18-TT. It is basically an 18 speed bike with road shifters and bullhorn bars, modeled after the Dahon Speed Pro TT and Vitesse P18. It combines the controls of the Speed Pro TT with the 2x9 drivetrain of the Vitesse P18.

After that upgrade, the bike worked well in all aspects, except for the brakes. The braking was unsatisfactory, due to the poor brake cable routing of the road shifter on the bullhorn bars and the extra friction contributed by the Travel Agents. There was a lot of friction within the system and braking was a chore as a lot of effort was needed to apply the brakes properly.

I have heard that some people have tried attaching a caliper brake to a Vitesse frame, but the rear caliper brake arm is far too short to reach the rims, even when extra long reach brake calipers are used. That was why I used Travel Agents with V brakes to attempt to solve this issue. However, the results were not good.

Finally, I had enough of the poor braking performance. I decided to try putting on caliper brakes on the Vitesse P18-TT, in a similar way to my own Dahon Boardwalk X20-R.

Besides the braking, the bullhorn bars also increased the reach from the flat handlebars. Usually this is good, as it allows you to stretch out more and ride in a more sporty position. However, if you are not vertically-blessed, this increased reach will make it strenuous to reach for the bullhorn bars. Therefore, I also decided to use a LitePro Stem to reduce the reach.

I shall let the pictures do the talking!

Tektro R559 Extra Long Reach calipers, with a very nice polished surface

Black LitePro Stem for 25.4mm handlebars

Right side of rear brake caliper. Using the default brake pads, the reach is slightly too short, which puts it too close to the tires.

With the special brake pads from Aican that extends the reach, the brake pad can be lowered to fit onto the rim properly.

The left side of the rear caliper does not require the special brake pad.

Most of the cases I have heard in which the rear brake calipers cannot reach the rim are on Vitesse frames. For this case, the insufficient reach was quite minor, and could be solved easily. It is possible that the mounting for the caliper brake is not consistent across different model years of Vitesse frames.

The front caliper brakes go on without much trouble. The front mounted bottle cage has been removed as it will interfere with the brake caliper arm when steering.

I tried the brakes with the stock Tektro brake pads, but the performance was quite horrible. It hardly provided any grip when the brake levers are squeezed. This is dangerous, which is why I had to solve it. Instead of getting the Koolstop brake pads which I am using on the Boardwalk, I decided to try out the SwissStop brake pads which is highly recommended.

Pricey, at almost S$40 a set from CRC

 I chose the green one as it seemed to fit my purpose and type of rims.

With the green brake pads from SwissStop, the braking performance was much improved. This has to be due to the better compound used to make the brake pads.

The other part of the upgrade is to add a stem to decrease the reach of the handlebar.

To insert the stem, one side of the bullhorn bar has to be completely cleared

Putting the stem such that the handlebar is behind the stem. This is rarely done, but seems to work fine. Fiber Grip is required to stop the stem rotating in the clamp.

Another view. Placing the stem behind the clamp theoretically has the effect of making the steering more sensitive. However, with the extra reach of the bullhorn bars, the gripping area is still in front of the clamp, and this should not be a big issue.

The brake cable housing coming out of the interrupter brake levers has to be moved as the stem interferes with proper braking function. This was solved by moving the interrupter brake levers further apart to get some clearance between the brake housing and the stem.

View of the rear brakes. With the caliper brakes, the cable routing looks neater compared to using V brakes with the Travel Agent.

Overall view of the Vitesse P18-TT

This is a successful upgrade that managed to improve the braking performance of the bike. Although it is still not very good due to the long cable housing involved, it is better than the previous version of Travel Agents and V brakes. The reach has also been reduced slightly, which makes it more comfortable for the rider.

The Dahon Boardwalk X20-R and the Vitesse P18-TT out on an extended test ride

Fork Accessory Bracket on the Dahon Front Luggage Mount

Want to add more front lights to your bike? Besides installing lights on the handlebar or handlepost, there are very few other places on the bike where you can fix a front light. I used to mount my front lights on the Minoura Space Grip, which is basically an expansion of your handlebar area.

It is good if you want to mount lots of accessories, however it makes the steering feel heavier, and the clamp may not be secure enough if you put heavy accessories on the space grip. The space grip was used to install the electric horn, the S-Sun light and the Busch & Muller IXON IQ front light. Ever since my electric horn was spoilt after getting soaked in heavy rain, I decided not to use the space grip, since I only had 2 front lights left to install.

The handlebar can accommodate only 1 front light, which means that I need to find another place to install my B&M front light. I came across this fork accessory bracket on SJS Cycles, which is specially made to be mounted on the front fork. Check out these fork accessory brackets.

Ever since I got my Ortlieb panniers, the front luggage mount on the head tube of my bike has been left empty. I decided to get this fork bracket to try it out, to see if I can make use of the space available. With some suitably long bolts, this fork bracket can be fixed securely to the frame.

The fork accessory bracket mounted on the Dahon front luggage mount. The clamp for the S-Sun front light is seen here.

Only a single bolt is required to mount the bracket. The rubber on the bracket will be compressed against the frame, giving a reasonably tight attachment.

Since I was not sure about the strength of this bracket, I first tested it with the lighter S-Sun front light. No problem there, the front light stayed on even on bumpy roads.

Next, I mounted the B&M front light, which is significantly heavier than the S-Sun front light.

Big front light!

The front light is tilted down slightly to shine on the road. This B&M light is meant to act as a steady headlight, to light up the path along dark stretches of road.

View from the top. The on/off button on top can be reached while cycling.

View from the front.

Even with the heavier B&M light mounted, there is no problem with the fork accessory bracket. Although it does wobble a bit on bumpy ground, it does not seem like it will break off. 

As discovered earlier, when the B&M light was mounted on the space grip, turning on the light will shut down the Cateye speedometer, due to the EM interference generated by the powerful front light. When mounted on the fork accessory bracket, I found that when the B&M light is on the high setting (40 lux), the EM interference is still present. However, when on low setting (10 lux), the B&M light no longer shuts down the speedo! I believe that this is due to the greater distance between the light and the speedometer computer unit. This allows me to use the front light and also have a working speedo at the same time, which is an unintended benefit.

Because this front light is mounted on the frame and not the handlebar, the light beam does not turn when you turn the handlebar. Not sure if this is good or bad, but is something to take note of.

Overall, I am quite pleased with this new accessory. It allows me to tidy up the handlebar area, as the space grip is no longer required to mount my front lights. Also, it allows me to use the B&M light without shutting down the speedometer. Lastly, it looks really unique with a large front light in front of the bike. There seems to be quite a few other types of brackets available, and with some clever jigging, I'm sure accessories can be fixed onto other parts of the bike too.

Modifications to Flamingo London NX7: Roller Skate Wheels!

Just a quick post on the roller wheels on my Flamingo London NX7. Previously, I had changed the roller wheels to the Ezy Wheels, as the stock roller wheels were quite poor. You can read more about it at the link below.

Modifications to Flamingo London NX7: Ezy Wheels

Those Ezy wheels were not really suitable for the Flamingo, as they were too small. Although they were smooth rolling, the tiny size made it vulnerable to getting stuck in crevices and gaps in the ground. Thus, I kept on searching for suitable roller wheels.

I finally found some suitable roller skate wheels in a roller skate shop at Novena! Thanks to 明天 who alerted me to the wheels. A set of 4 wheels was obtained, and they are of similar size to the original roller wheels on the Flamingo.

Originally meant for roller skates!

Good quality wheels, at an affordable $10 per set

However, as with most modifications, it is not as easy as just swapping the wheels. The original roller wheels uses M6 bolts as the axle for the wheels, and this bolt size has to be maintained as there are corresponding M6 screw threads on the bike rear rack. These roller skate wheels have a larger hole in the center, which is about M8 in size. If I had used just M6 bolts to install them, there would be a lot of play between the wheels and the axle, which will quickly destroy the wheels.

Thus, I had to find suitable shims to enlarge the axle, at the portion where the wheel bearing rests on the axle. Only then could the wheels be installed properly.

 New roller wheels for the Flamingo

These wheels are quite good, as they are nice and round, unlike the original ones which had bumps and dents, that made it difficult to roll the bike. The bearings are also smoother. 

Finally, I have found the ideal roller wheels for the bike! These wheels roll well, are of a good size for rolling over uneven ground, and are round enough to roll smoothly and easily.